The fundamental goals of this program project are: (1) to identify those critical variables which must be measured to comprehensively describe the structure and function of the cardiovascular system in health and disease, (2) to develop necessary research and clinical instruments capable of sensing or recording the most important of these variables objectively and ultimately quantitatively in man, preferably by non-invasive techniques, (3) to evaluate and apply these new and non-conventional sources of vital data to normal subjects and patients with various forms of cardiovascular diseases, (4) to stimulate commercial production of new instruments with demonstrated potential so that they can become widely available to the scientific community at minimal cost.